| Message ID | 2c3b793fc23910f8fe15033b2b35e53b0b5dbaf3.1484839971.git.jpoimboe@redhat.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Thu, 19 Jan 2017, Josh Poimboeuf wrote: > Expose the per-task patch state value so users can determine which tasks > are holding up completion of a patching operation. > > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> > Reviewed-by: Petr Mladek <pmladek@suse.com> > Reviewed-by: Miroslav Benes <mbenes@suse.cz> > --- > Documentation/filesystems/proc.txt | 18 ++++++++++++++++++ > fs/proc/base.c | 15 +++++++++++++++ > 2 files changed, 33 insertions(+) > > diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt > index 72624a1..85c501b 100644 > --- a/Documentation/filesystems/proc.txt > +++ b/Documentation/filesystems/proc.txt > @@ -44,6 +44,7 @@ Table of Contents > 3.8 /proc/<pid>/fdinfo/<fd> - Information about opened file > 3.9 /proc/<pid>/map_files - Information about memory mapped files > 3.10 /proc/<pid>/timerslack_ns - Task timerslack value > + 3.11 /proc/<pid>/patch_state - Livepatch patch operation state > > 4 Configuring procfs > 4.1 Mount options > @@ -1886,6 +1887,23 @@ Valid values are from 0 - ULLONG_MAX > An application setting the value must have PTRACE_MODE_ATTACH_FSCREDS level > permissions on the task specified to change its timerslack_ns value. > > +3.11 /proc/<pid>/patch_state - Livepatch patch operation state > +----------------------------------------------------------------- > +When CONFIG_LIVEPATCH is enabled, this file displays the value of the > +patch state for the task. > + > +A value of '-1' indicates that no patch is in transition. > + > +A value of '0' indicates that a patch is in transition and the task is > +unpatched. If the patch is being enabled, then the task hasn't been > +patched yet. If the patch is being disabled, then the task has already > +been unpatched. > + > +A value of '1' indicates that a patch is in transition and the task is > +patched. If the patch is being enabled, then the task has already been > +patched. If the patch is being disabled, then the task hasn't been > +unpatched yet. > + Despite my review I thought about this some more. I think the logic make sense internally but when exposed it can be confusing. We do not export klp_target_state value, so users have to know if a patch is being enabled or disabled. Of course, they should know that, but I guess they'd like to use an userspace tool for this. Such tool needs to look at /proc/<pid>/patch_state to find out which tasks are blocking the completion and that is it. No more information anywhere. We can either export klp_target_state, or change /proc/<pid>/patch_state to show only two states - task is in transition (1), task is patched (0). What do you think? Miroslav
On Tue, Jan 31, 2017 at 03:31:39PM +0100, Miroslav Benes wrote: > On Thu, 19 Jan 2017, Josh Poimboeuf wrote: > > > Expose the per-task patch state value so users can determine which tasks > > are holding up completion of a patching operation. > > > > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> > > Reviewed-by: Petr Mladek <pmladek@suse.com> > > Reviewed-by: Miroslav Benes <mbenes@suse.cz> > > --- > > Documentation/filesystems/proc.txt | 18 ++++++++++++++++++ > > fs/proc/base.c | 15 +++++++++++++++ > > 2 files changed, 33 insertions(+) > > > > diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt > > index 72624a1..85c501b 100644 > > --- a/Documentation/filesystems/proc.txt > > +++ b/Documentation/filesystems/proc.txt > > @@ -44,6 +44,7 @@ Table of Contents > > 3.8 /proc/<pid>/fdinfo/<fd> - Information about opened file > > 3.9 /proc/<pid>/map_files - Information about memory mapped files > > 3.10 /proc/<pid>/timerslack_ns - Task timerslack value > > + 3.11 /proc/<pid>/patch_state - Livepatch patch operation state > > > > 4 Configuring procfs > > 4.1 Mount options > > @@ -1886,6 +1887,23 @@ Valid values are from 0 - ULLONG_MAX > > An application setting the value must have PTRACE_MODE_ATTACH_FSCREDS level > > permissions on the task specified to change its timerslack_ns value. > > > > +3.11 /proc/<pid>/patch_state - Livepatch patch operation state > > +----------------------------------------------------------------- > > +When CONFIG_LIVEPATCH is enabled, this file displays the value of the > > +patch state for the task. > > + > > +A value of '-1' indicates that no patch is in transition. > > + > > +A value of '0' indicates that a patch is in transition and the task is > > +unpatched. If the patch is being enabled, then the task hasn't been > > +patched yet. If the patch is being disabled, then the task has already > > +been unpatched. > > + > > +A value of '1' indicates that a patch is in transition and the task is > > +patched. If the patch is being enabled, then the task has already been > > +patched. If the patch is being disabled, then the task hasn't been > > +unpatched yet. > > + > > Despite my review I thought about this some more. I think the logic make > sense internally but when exposed it can be confusing. We do not export > klp_target_state value, so users have to know if a patch is being enabled > or disabled. Of course, they should know that, but I guess they'd like to > use an userspace tool for this. Such tool needs to look at > /proc/<pid>/patch_state to find out which tasks are blocking the > completion and that is it. No more information anywhere. > > We can either export klp_target_state, or change /proc/<pid>/patch_state > to show only two states - task is in transition (1), task is patched (0). > > What do you think? Isn't this information already available in /sys/kernel/livepatch/<patch>/{enabled,transition}?
On Tue, 31 Jan 2017, Josh Poimboeuf wrote: > On Tue, Jan 31, 2017 at 03:31:39PM +0100, Miroslav Benes wrote: > > On Thu, 19 Jan 2017, Josh Poimboeuf wrote: > > > > > Expose the per-task patch state value so users can determine which tasks > > > are holding up completion of a patching operation. > > > > > > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> > > > Reviewed-by: Petr Mladek <pmladek@suse.com> > > > Reviewed-by: Miroslav Benes <mbenes@suse.cz> > > > --- > > > Documentation/filesystems/proc.txt | 18 ++++++++++++++++++ > > > fs/proc/base.c | 15 +++++++++++++++ > > > 2 files changed, 33 insertions(+) > > > > > > diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt > > > index 72624a1..85c501b 100644 > > > --- a/Documentation/filesystems/proc.txt > > > +++ b/Documentation/filesystems/proc.txt > > > @@ -44,6 +44,7 @@ Table of Contents > > > 3.8 /proc/<pid>/fdinfo/<fd> - Information about opened file > > > 3.9 /proc/<pid>/map_files - Information about memory mapped files > > > 3.10 /proc/<pid>/timerslack_ns - Task timerslack value > > > + 3.11 /proc/<pid>/patch_state - Livepatch patch operation state > > > > > > 4 Configuring procfs > > > 4.1 Mount options > > > @@ -1886,6 +1887,23 @@ Valid values are from 0 - ULLONG_MAX > > > An application setting the value must have PTRACE_MODE_ATTACH_FSCREDS level > > > permissions on the task specified to change its timerslack_ns value. > > > > > > +3.11 /proc/<pid>/patch_state - Livepatch patch operation state > > > +----------------------------------------------------------------- > > > +When CONFIG_LIVEPATCH is enabled, this file displays the value of the > > > +patch state for the task. > > > + > > > +A value of '-1' indicates that no patch is in transition. > > > + > > > +A value of '0' indicates that a patch is in transition and the task is > > > +unpatched. If the patch is being enabled, then the task hasn't been > > > +patched yet. If the patch is being disabled, then the task has already > > > +been unpatched. > > > + > > > +A value of '1' indicates that a patch is in transition and the task is > > > +patched. If the patch is being enabled, then the task has already been > > > +patched. If the patch is being disabled, then the task hasn't been > > > +unpatched yet. > > > + > > > > Despite my review I thought about this some more. I think the logic make > > sense internally but when exposed it can be confusing. We do not export > > klp_target_state value, so users have to know if a patch is being enabled > > or disabled. Of course, they should know that, but I guess they'd like to > > use an userspace tool for this. Such tool needs to look at > > /proc/<pid>/patch_state to find out which tasks are blocking the > > completion and that is it. No more information anywhere. > > > > We can either export klp_target_state, or change /proc/<pid>/patch_state > > to show only two states - task is in transition (1), task is patched (0). > > > > What do you think? > > Isn't this information already available in > /sys/kernel/livepatch/<patch>/{enabled,transition}? transition no. That only gives the hint that something is happening with the patch. But yes, enabled is the one I wanted. I don't know how I missed that. Combined with /proc/<pid>/task it is exactly what a tool needs. Miroslav
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 72624a1..85c501b 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -44,6 +44,7 @@ Table of Contents 3.8 /proc/<pid>/fdinfo/<fd> - Information about opened file 3.9 /proc/<pid>/map_files - Information about memory mapped files 3.10 /proc/<pid>/timerslack_ns - Task timerslack value + 3.11 /proc/<pid>/patch_state - Livepatch patch operation state 4 Configuring procfs 4.1 Mount options @@ -1886,6 +1887,23 @@ Valid values are from 0 - ULLONG_MAX An application setting the value must have PTRACE_MODE_ATTACH_FSCREDS level permissions on the task specified to change its timerslack_ns value. +3.11 /proc/<pid>/patch_state - Livepatch patch operation state +----------------------------------------------------------------- +When CONFIG_LIVEPATCH is enabled, this file displays the value of the +patch state for the task. + +A value of '-1' indicates that no patch is in transition. + +A value of '0' indicates that a patch is in transition and the task is +unpatched. If the patch is being enabled, then the task hasn't been +patched yet. If the patch is being disabled, then the task has already +been unpatched. + +A value of '1' indicates that a patch is in transition and the task is +patched. If the patch is being enabled, then the task has already been +patched. If the patch is being disabled, then the task hasn't been +unpatched yet. + ------------------------------------------------------------------------------ Configuring procfs diff --git a/fs/proc/base.c b/fs/proc/base.c index 16ed964..6d773be 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2797,6 +2797,15 @@ static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, return err; } +#ifdef CONFIG_LIVEPATCH +static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) +{ + seq_printf(m, "%d\n", task->patch_state); + return 0; +} +#endif /* CONFIG_LIVEPATCH */ + /* * Thread groups */ @@ -2896,6 +2905,9 @@ static const struct pid_entry tgid_base_stuff[] = { REG("timers", S_IRUGO, proc_timers_operations), #endif REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations), +#ifdef CONFIG_LIVEPATCH + ONE("patch_state", S_IRUSR, proc_pid_patch_state), +#endif }; static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx) @@ -3276,6 +3288,9 @@ static const struct pid_entry tid_base_stuff[] = { REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations), REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations), #endif +#ifdef CONFIG_LIVEPATCH + ONE("patch_state", S_IRUSR, proc_pid_patch_state), +#endif }; static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)